class IndexService {
  log(str:string){
    console.log("熊", str);
  }
}


class IndexController{
  private indexService;
  constructor() {
    this.indexService = new IndexService();
  }
  info(){
    this.indexService.log('ahhh');
  }
}

//1. 傻瓜写法
const indexController = new IndexController();
indexController.info(); // ahhh
